Long-term Outcome of Renal Transplantation in Patients with Congenital Lower Urinary Tract Malformations: A Multicenter Study

A systematic review of kidney transplantation outcomes in patients with end-stage renal disease due to childhood lower urinary tract malformations

PURPOSE

Patients with lower urinary tract malformations (LUTM) were suspended from kidney transplantation (KT) programs in the past due to various concerns. Consequently, only a limited number of studies have explored this topic at hand. In this study, our objective was to perform a systematic review (SR) to evaluate the current evidence regarding KT outcomes as well as patient survival (PS), postoperative complications and urinary tract infections (UTI) in individuals with childhood LUTM.

METHODS

The search encompassed databases of Web of Science, Medline (via PubMed), and Embase (via Scopus) to identify all studies reporting outcomes on KT for patients with LUTM. The research included articles published in English from January 1995 till September 2023.

RESULTS

Of the 2634 yielded articles, 15 met the inclusion criteria, enrolling a total of 284,866 KT patients. There was significantly better 5-year graft survival (GS) in recipients with LUTM compared to the control group (RR, 1.04; 95% CI 1.02-1.06); while GS at 1-year and 10-year, and PS at 1-year, 5-year and 10-year were similar between groups. On the other hand, the postoperative UTI rate was significantly higher in the LUTM group (RR: 4.46; 95% CI 1.89-10.51). However, data on serum creatinine and estimated glomerular filtration rate on follow-up were insufficient.

CONCLUSION

GS and PS rates appear to be similar in patients with childhood LUTM and those with normal lower urinary tract functions. Despite a higher postoperative UTI rate within this patient group, it appears that this has no effect on GS rates.

Kidney function and transplants in prune belly syndrome: a scoping review

BACKGROUND

Children with prune belly syndrome (PBS) are at higher risk of developing kidney dysfunction and requiring kidney replacement therapy (KRT). While studies have described surgical and survival outcomes in these populations, there has yet to be a focused synthesis of evidence regarding kidney outcomes in this population. Here, the focus of this scoping review was to highlight knowledge gaps and report standards on kidney outcomes in PBS of all ages.

METHODS

Following scoping review methodology, EMBASE, MEDLINE, and Scopus were searched for peer-reviewed literature that describe kidney outcomes in PBS. All studies with a broad set of kidney outcomes (such as kidney function measures, chronic kidney disease (CKD), KRT and associated outcomes) were included. Findings were summarized and qualitatively synthesized.

RESULTS

Of the 436 unique records identified, 25 were included for synthesis. A total of 17 studies (441 patients) reported on kidney insufficiency outcomes, with an estimated prevalence of CKD ranging from 8 to 66%. A total of 15 studies (314 patients) described KRT, primary kidney transplant, and outcomes. Of these, the age for KRT ranged from 4 to 21 years, and graft survival ranged from 22 to 87% by last follow-up (range 1.3-27 years).

CONCLUSIONS

There is significant variability in studies reporting kidney outcomes in PBS which limits meaningful synthesis. There is a need for future studies with comprehensive reporting of confounders and drivers for kidney insufficiency in PBS.

Clinical considerations in adults with history of posterior urethral valves

INTRODUCTION

Management of patients with posterior urethral valves (PUV) is commonplace for many pediatric urologists, however adult providers may be far less familiar with this diagnosis, its management and long-term ramifications. As urologic management of these patients has evolved, clinical outcomes have substantially improved with many more patients now surviving into adulthood. These patients remain at increased risk of morbidity due to their condition and therefore are likely to benefit from long term follow-up with adult providers.

OBJECTIVE

In this review we analyze the psychosocial impacts of PUV on adults, evaluate long term transplant outcomes in PUV patients and discuss effective clinical management strategies of bladder dysfunction in adult PUV patients.

STUDY DESIGN

A retrospective literature review was performed using the MEDLINE (Pubmed) electronic database using key words such as "posterior urethral valve", "quality of life", "sexual function", "transplant outcomes", "bladder dysfunction", "mitrofanoff" etc. to identify relevant studies.

RESULTS

Generally, the quality of life of PUV patients is good, those suffering from renal insufficiency or lower urinary tract symptoms, specifically incontinence, appear to be a group that may benefit from more intensive follow-up. Good long-term kidney transplant (KT) function and survival can be achieved in patients with PUV. Rigorous management to optimize bladder function and close follow-up, are key for long term graft survival after KT.

DISCUSSION

The chronicity of PUV warrants adult providers to be not only well versed in the pathophysiology of the disease, but well prepared to care for these patients as they transition into adulthood.

CONCLUSION

Additional studies addressing psychosocial, clinical and transplant outcomes of adults with PUV are necessary to develop optimal long-term follow-up regimens for these patients.

Retrospective analysis of percutaneous intervention of the renal artery in transplanted kidneys in children and adolescents at a tertiary public hospital

BACKGROUND

This study evaluated the long-term effects of percutaneous intervention in children and adolescents with transplant renal artery stenosis (TRAS).

METHODS

Twenty patients had significant stenosis (>50%) and underwent percutaneous transluminal angioplasty (PTA/stenting) (TRAS group-intervention); 14 TNS (non-significant group -control) patients did not have significant stenosis (≤50%) and were treated clinically. The combined primary endpoints were death from all causes and late graft failure. The secondary endpoints were serum creatinine (SCr), systolic blood pressure (SBP), and diastolic blood pressure (DBP).

RESULTS

No statistically significant difference was found between TRAS-Intervention(N = 20) and TNS groups-Control (N = 14) for these clinical parameters: deaths, 1 (5.0%) vs. 0 (0.0%) (p = 1.000) and graft loss, 4 (20.0%) vs. 2 (14.3%) (p = 1.000). For the secondary endpoints, after 1 month and 1 year the values of SCr, SBP, and DBP were similar between the two groups but not statistically significant.

DISCUSSION

In the TRAS group (intervention), the stent implantation was beneficial for treating refractory hypertension and reducing blood pressure (BP) in children and adolescents. Despite the outcomes being similar in the two groups, it can be inferred that the patients in the TRAS group (intervention) would have had a worse outcome without the percutaneous intervention.

CONCLUSION

TRAS treatment with stenting can be considered for children and adolescents. Because the sample in the present study comprised of only a specific population, further studies are needed for generalization.

TRIAL REGISTRATION

The trial was registered at clinictrials.gov with trial registration number NCT04225338.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Bladder salvage in children with congenital lower urinary tract malformations undergoing renal transplant

INTRODUCTION

Patients with Congenital Lower Urinary Tract Malformations (CLUTM) have increased risk of post-transplant complications if bladder dysfunction is not addressed. Pretransplant assessment may be difficult if urinary diversion has been previously applied. In case of low capacity and/or low compliance and/or high-pressure overactive bladder, transplantation into a diverted or augmented system may be required. We hypothesised that a bladder optimization pathway may help identify potentially salvageable bladders and prevent unnecessary bladder diversion or augmentation. We propose a structured bladder optimisation and assessment programme for safe transplant and native bladder salvage.

MATERIAL AND METHODS

Data of 130 children who underwent renal transplant between 2007 and 2018 were retrospectively collected and analysed. All patients with CLUTM were assessed by urodynamic study. Bladder optimisation: Low compliance bladders were managed with anticholinergics and/or Botulinum toxin A (BtA) injections. Those who had urinary diversion for their pathology underwent a structured assessment and optimisation process with undiversion/anticholinergics/BtA/bladder cycling/Clean Intermittent Catheterisation (CIC)/Suprapubic catheter (SPC) as indicated. Details of medical and surgical management were collected (Figure 1).

RESULTS

Between 2007 and 2018, 130 renal transplants were done. Of these, 35 (27%) had associated CLUTM (PUV in 15, neurogenic bladder dysfunction in 16, other pathology in 4) which was managed in our centre. Ten patients needed initial diversion in the form of vesicostomy (2) or ureterostomy (8) to manage primary bladder dysfunction. The median age at transplant was 7.8 years (range 2.5-19.6). After bladder assessment and optimisation, a safe bladder was demonstrated in 5 of 10 with initial diversion leading to transplant into native bladder (without augmentation). Overall, of the 35 patients, 20 (57%) had transplant into native bladder, 11 patients had ileal conduits and 4 had bladder augmentation. Eight required help with drainage: three with CIC, four with Mitrofanoff, and one had reduction cystoplasty.

CONCLUSION

With a structured bladder optimisation and assessment programme, safe transplant and 57% native bladder salvage is achievable in children with CLUTM.

Utility of Pre-Transplant Bladder Cycling for Patients With a Defunctionalized Bladder. A Randomized Controlled Trial

OBJECTIVE

To study the necessity of pre-transplant programmed bladder cycling (PBC) in patients with defunctionalized bladder (DB).

METHOD

This RCT included renal transplant (RT) candidates with DB. Eligible patients were assigned to 2 groups, group I underwent PBC before RT and group II underwent direct RT into the DB. The primary outcome was to assess the efficacy of PBC in improving post- RT bladder capacity. Secondly, to compare its impact on early urological complications and 3-month voiding function and 1-year graft function and survival. Graft function was evaluated using serum creatinine and eGFR using MDRD equation.

RESULTS

Groups I included 23 patients and group II included 20 patients. The mean ±SD of bladder capacity was 88.7±11.7mL and 90.6 ±9.8mL in both groups, respectively (P = .5). In group I, PBC increased bladder capacity to 194.7 ±21.2 mL (P < .001). Targeted bladder capacity was achieved in 19 (82.6 %) patients and 2 patients developed UTI. At 3-months, bladder capacity, compliance and bladder contractility index improved significantly in both groups with a significant reduction in maximum detrusor pressure with no significant difference between both groups (P = .3,0.4, 0.2 and 0.8, respectively). Urinary leakage occurred in one (4.3%) and 3 patients (15%) in group 1 and 2, respectively (P = .2). At 1-year, no statistically significant differences in the median (IQR) serum creatinine (P = .05) and eGFR (P = .07) between both groups were noted.

CONCLUSION

Pre-transplant PBC for DB-patients provided no clinical advantage concerning post-operative urological complication, urodynamic criteria and graft function and survival.

MEDIUM AND LONG-TERM CLINICAL OUTCOMES OF KIDNEY TRANSPLANTATION IN PATIENTS WITH PRUNE BELLY SYNDROME: A SINGLE-CENTRE EXPERIENCE

OBJECTIVES

To present the medium and long-term outcomes of kidney transplantation performed in patients with Prune Belly Syndrome (PBS) which is one of the congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

Thirteen kidney transplantations were performed in nine patients with PBS from January 1994 to December 2020. Demographics, surgical features, graft and patient survival rates were analysed. Survival outcomes was compared with 106 age- and donor-type matched controls who underwent transplantation because of non-urological causes.

RESULTS

The median ages of PBS patients at the time of first and second transplantation were 19 and 34 years old, respectively. One patient had postoperative Clavien grade 3a complication. Eight of 13 transplants are still functional at the last follow-up. Eight patients underwent pre-transplant urological operations in preparation for kidney transplantation, while four patients underwent urological operations in the post-transplant period. Graft survival for PBS transplants at 5, 10 and 15 years were 90.9%, 57.7% and 38.5%, respectively. Graft survival for control cohort at 5, 10 and 15 years were 89.9%, 80% and 74%, respectively. The patient and graft survival rates were similar between PBS and control groups (p=0.449, p=0.134, respectively).

CONCLUSION

This single-centre study showed that the medium term graft survival rates in patients with PBS are encouraging and comparible to non-CAKUT transplant patients, however long-term graft survival rates were found to be proportionally inferior. To help determine the reasons for long-term transplant kidney function deterioration and how to improve them we suggest that multi-centre international collaboration will be needed.

Chronic Kidney Disease in Boys with Posterior Urethral Valves-Pathogenesis, Prognosis and Management

Posterior urethral valves (PUV) are the most common form of lower urinary tract obstructions (LUTO). The valves can be surgically corrected postnatally; however, the impairment of kidney and bladder development is irreversible and has lifelong implications. Chronic kidney disease (CKD) and bladder dysfunction are frequent problems. Approximately 20% of PUV patients will reach end-stage kidney disease (ESKD). The subvesical obstruction in PUV leads to muscular hypertrophy and fibrotic remodelling in the bladder, which both impair its function. Kidney development is disturbed and results in dysplasia, hypoplasia, inflammation and renal fibrosis, which are hallmarks of CKD. The prognoses of PUV patients are based on prenatal and postnatal parameters. Prenatal parameters include signs of renal hypodysplasia in the analysis of fetal urine. Postnatally, the most robust predictor of PUV is the nadir serum creatinine after valve ablation. A value that is below 0.4 mg/dl implies a very low risk for ESKD, whereas a value above 0.85 mg/dl indicates a high risk for ESKD. In addition, bladder dysfunction and renal dysplasia point towards an unbeneficial kidney outcome. Experimental urinary markers such as MCP-1 and TGF-β, as well as microalbuminuria, indicate progression to CKD. Until now, prenatal intervention may improve survival but yields no renal benefit. The management of PUV patients includes control of bladder dysfunction and CKD treatment to slow down progression by controlling hypertension, proteinuria and infections. In kidney transplantation, aggressive bladder management is essential to ensure optimal graft survival.

Outcomes of kidney‐transplanted patients with history of intestinal reconstruction of the urinary tract

Background

Methods

Results

Conclusions

[Lower urinary tract symptoms and urinary incontinence in renal transplant recipients and candidates: The French guidelines from CTAFU]

OBJECTIVE

To propose surgical recommendations for the management of lower urinary tract symptoms (LUTS) and urinary incontinence in kidney transplant recipients and candidates.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU focusing on medical and surgical treatment of LUTS and urinary incontinence in kidney transplant recipients and candidates. References were assessed according to a predefined process to propose recommendations with levels of evidence.

RESULTS

Functional bladder capacity and bladder compliance are impaired during dialysis. LUTS, related to pre-kidney transplantion alterations, frequently improve spontaneously after kidney transplantation. LUTS secondary to benign prostatic hyperplasia (BPH) may be underestimated before kidney transplantation due to oliguria, low bladder compliance and low bladder capacity. In LUTS associated with BPH, anticholinergics require dosage adjustment with creatinine clearance. If surgery is indicated after kidney transplantation, procedure can be safely performed in the early post-transplant course after removal of ureteral stent. Surgical management of urinary incontinence does not seem to be associated with an icreased risk for infectious complications in kidney transplant recipients. Particular attention should be paid to the management of postvoid residual and bladder pressures in case of neurological bladder disease. Optimal care of neurological bladder should be provided prior to transplantation: with a cautious management, and despite an increased occurrence of febrile urinary tract infections, transplant survival is not compromised.

CONCLUSION

These recommendations must contribute to improve the management of lower urinary tract symptoms and urinary incontinence in kidney transplant patients and kidney transplant candidates.

Renal Transplants Due to Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) Have Better Graft Survival Than Non-CAKUT Controls: Analysis of Over 10,000 Patients

OBJECTIVE

To determine whether graft survival for patients with congenital anomalies of the kidney and urinary tract (CAKUT) is impaired compared to non-CAKUT counterparts.

METHODS

The United States Renal Data System (USRDS) is a national data system that has collected information about end stage renal disease (ESRD) and renal transplantation since 1995. We identified 10,635 first-time renal transplant patients with ESRD attributed to a CAKUT diagnosis transplanted between 1995 and 2018, with follow-up of 7.9 ± 5.8 years. We matched 1:1 with non-CAKUT transplant recipients, using age at transplant, sex, race, year of transplant, and donor-type. We compared renal transplant death-censored graft survival between CAKUT vs non-CAKUT controls, with further stratification for age at transplant and lower urinary tract malformations (LUTM) vs upper urinary tract malformations (UUTM).

RESULTS

Graft survival was better in CAKUT patients with a 5-year survival of 83.3% vs 79.3% (P< .001), and CAKUT status infers a hazard ratio of 0.878 for graft failure on multivariable analysis with Cox regression. Favorability of CAKUT status persisted when stratifying for both pediatric (80.3 vs 77.6% P< .001) and adult (84.5 vs 81.4% P< .001) age groups. Looking within the CAKUT population: comparison of LUTM to UUTM yielded no difference, implying that LUTM is not a risk factor for graft failure. Examining pediatric LUTM alone, graft survival was not better than matched non-CAKUT counterparts with 5-year graft survival of 69%-75% for LUTM adolescents.

CONCLUSION

Renal transplant graft survival is better overall in CAKUT patients as opposed to non-CAKUT counterparts. Pediatric LUTM patients have similar graft survival to controls.

Comparison of the outcomes of the pediatric kidney transplantation between recipients below and above 15 kg: a single center retrospective study

BACKGROUND

The renal transplantation is the best treatment for end-stage renal disease in children. We present the findings of an analysis of our institution's paediatric transplant outcomes comparing recipients under 15 kg, who represent this potentially higher risk group, to those above 15 kg.

METHODS

We retrospectively identified consecutive paediatric kidney transplants from a prospectively collected database for analysis. We included all recipients under the age of 18 years at the time of transplant between 2006 and 2018 without any exclusion criteria. The primary outcome was death-censored graft survival at 1 year, 5 years and 10 years.

RESULTS

109 paediatric kidney transplants were performed in 100 children. Graft survival in the all population was 98%, 96% and 76% at 1 year, 5 years and 10 years, respectively. Recipient weight below 15 kg was not found to be a risk factor of graft loss. Overall, we found no individual factor to be statistically significantly associated with renal graft lost. The overall complication rate was 16% (18/109) with 12 early complications (11%) and 6 late ones (5%).

CONCLUSION

Kidney transplantation in children weighing < 15 kg seems safe and offers the same patient and graft survival outcomes as in other (> 15 kg) pediatric recipients with equally low complication rates.

Trasplante renal en paciente con pared abdominal compleja: síndrome de abdomen en ciruela pasa

Introducción. Se presenta un paciente con falla renal crónica secundaria a hidroureteronefrosis bilateral, con antecedente de síndrome de abdomen en ciruela pasa (prune belly), en quien se realiza trasplante renal. El objetivo de este reporte de caso es exponer una anomalía congénita, con baja incidencia mundial y en menor proporción asociado a trasplante renal, con énfasis en la dificultad para la técnica quirúrgica dada por la hipoplasia de los músculos de la pared abdominal. Métodos. Revisión de Historia clínica, Consentimiento Informado. Búsqueda de la literatura. Caso clínico. En cirugía se identifica ausencia de músculos de la pared abdominal y fibrosis de las venas Iliaca externa y común derecha. Se realiza abordaje bajo técnica de Gibson contralateral, con trasplante renal sin complicaciones. Presentó adecuada evolución en seguimiento ambulatorio. Discusión. El síndrome de abdomen en ciruela pasa (prune belly) es una anomalía congénita de baja incidencia, con pocos reportes asociados a trasplante renal. El reto quirúrgico está dado por la ausencia de músculos de la pared abdominal, que aumentan los riesgos por posibles complicaciones, como la lesión de los vasos epigástricos inferiores. Para el cierre de pared abdominal en trasplante renal, se describe en dos planos, que en este caso se realiza sobre fascia muscular y piel. Aun siendo un reto, el paciente presenta adecuada evolución postoperatoria.